From d5f812e0b140c38d05ab578a9a8e7091536fb5e1 Mon Sep 17 00:00:00 2001
From: "Kevin P. Fleming" <kpfleming@digium.com>
Date: Thu, 7 Sep 2006 00:41:27 +0000
Subject: [PATCH] don't try to get the length of the string in the
 ast_dynamic_str object unless we know there is actually one there

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@42185 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
 main/utils.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/main/utils.c b/main/utils.c
index 3a8e85f06e..edb4102e05 100644
--- a/main/utils.c
+++ b/main/utils.c
@@ -1199,7 +1199,7 @@ int ast_dynamic_str_thread_build_va(struct ast_dynamic_str **buf, size_t max_len
 	struct ast_threadstorage *ts, int append, const char *fmt, va_list ap)
 {
 	int res;
-	int offset = append ? strlen((*buf)->str) : 0;
+	int offset = (append && (*buf)->len) ? strlen((*buf)->str) : 0;
 
 	res = vsnprintf((*buf)->str + offset, (*buf)->len - offset, fmt, ap);